The present invention relates to an exhaust gas pressure control valve disposed in an exhaust system of the engine for reducing the flow of the exhaust gas. Particularly, the present invention relates to an exhaust gas pressure control valve disposed between a muffler and outside or between an engine and muffler which reduces engine noise generated while exhausting gas.
The exhaust gas pressure control valve, which is disposed along the exhaust gas pipeline, is used as an exhaust break system for diesel vehicles such as truck and bus or as a warm-up system while the engine is idling during cold days. Japan unexamined patent publication No. 2011-032955 discloses an exhaust gas control valve which has simple configuration and allows smooth rotation regardless of the size of the exhaust gas pressure. Patent Literature 1: JP Unexamined Patent Publication No. 2011-032955 A1
However, the exhaust gas pressure control valve disclosed in '955 is formed with predetermined thickness, and the valve axis of the exhaust gas pressure control valve is disposed traverse to the center of the exhaust gas pipeline. Therefore, when the exhaust gas pressure system valve opens completely, the valve thickness and valve axis acts as a resistance against the system. In other word, the cross-sectional area of the exhaust gas pipeline becomes smaller by amount of the valve thickness and projection area of the valve axis at an exhaust gas pressure control valve.